Elected as a Member of Parliament in 2012, Pato was immediately appointed Foreign Minister, and has since played prominent roles, often as chairman, in the Pacific Islands Forum (including representing the Prime Minister at the Leaders' meeting), the Melanesian Spearhead Group, and the African, Caribbean and Pacific Group of States.

Pato has also chaired and co-chaired high-level sessions at the United Nations. Pato has conducted many significant negotiations on behalf of Papua New Guinea, including on delicate topics such as the Manus Island refugee arrangements. He has met in bilateral and multilateral meetings, as well as on social occasions, with his counterpart foreign ministers and national leaders of other countries.

As an envoy of Prime Minister O’Neill, Pato has delivered the Country Statement for Papua New Guinea on several occasions at the United Nations General Assembly, most recently on 29 September 2018.

Pato held the Immigration portfolio 2012-2017. In 2017, he was reappointed as Minister for Foreign Affairs and in addition was assigned the trade Portfolio.

Pato will Chair the Ministerial Session of the 2018 APEC Economic Leaders Summit in Port Moresby, Papua New Guinea. The event is the largest and most significant event hosted by the country in its history.

Prior to becoming a politician in 2012, Pato was a prominent practising lawyer in PNG, and was involved in significant cases. He was Managing Partner, Steeles Lawyers, which later re-established as Pato Lawyers, with Pato remaining as Managing Partner.